Sirius hadn't been expecting Remus to agree with him about Kingsley's choice to save the Boardman girl. He'd assumed that Remus would want to preserve the harmony in the Outsiders as much as possible. He offered him a quick glance of solidarity before returning his attention to what Kingsley was saying.
He was glad that Kingsley made the attempt to explain his motives, but when Kingsley disparaged their House and called them 'ridiculous', Sirius felt his anger rise, displacing the bitterness and curiosity. The last sentence shoved him, almost brutally, into cold fury.
He placed his wine glass on the table, very carefully and very deliberately. "You accuse me--me--of being 'holier-than-thou'? I have never thought myself better than you. I know I'm all but useless here. If I could do more, be more, help more, I'd do it. You say it's a Gryffindor thing to ignore 'certain truths'? All I have--all that most of the Outsiders have--is 'emotional right or wrongs'. We don't have freedom. We don't have justice. If there was justice available to us, we'd have the freedom to be what we should have been. I think of all the dreams I had--they're gone, Kings. I can never get back what I've done and what I've lost. The emotional shit--the guilt, the anger, the regret, the pain--is all I've got. I have to practically rip whatever happiness I can get out of the gods' fingers because it's certainly not being handed to me, and you want to say I'm being 'holier-than-thou'? Fuck that!" Sirius paused to calm himself. His voice had been rising throughout his tirade until he'd shouted the last bit. He took a deep breath and then went on.
"All I was asking you why this girl is more important to you than Frank's boy. You and Frank were always close--why not save Neville? I was asking for an explanation, because sometimes it's difficult to see things from any other angle than emotion when you have to live like this."